Traditionally ice skates are built so as to comprise a hardened steel blade suitably secured to a metal body or frame which includes elevated toe and heel platforms secured to the underside of a boot. In the best quality skates made today, the blades and body or frame are made of steel with the blade being secured to a tubular section of the frame through spot welding.
Several difficulties exist with skates utilizing a metal blade-supporting body or frame. First, in fabricating a metal blade-supporting body to a blade, it is conventional practice to use eight different steel components which are variously spot welded together. Not only is there a problem in insuring the integrity of such welds, but in welding the blade to the body there is the constant danger of weakening or reducing the temper of the hardened steel blade. As will be seen in the present invention, there are two major components, a monolithic plastic body and a hardened steel blade, which are readily connected by fastening means which in no way affect the critical temper of the hardened blade. Thus fewer major components, less expensive materials and fewer assembly operations are required with the present invention.
Next, it has become increasingly difficult to obtain consistently high quality steel for use in such blade-supporting bodies. As lesser quality steel has been used, breakage and rusting of such bodies has become more frequent.
It is also known that if the blade-supporting body can be suitably made of a plastic material, an important saving in weight can be realized, thereby importantly reducing energy expenditure and thereby lessening skater fatigue. Each skate made in accordance with the present invention is on the order of 4 ounces lighter than its all-steel counterpart. It is estimated that an aggressive hockey forward takes over 4000 strides and thus likely skates several miles during a game. At the same time, an Olympic track study determined that the addition of 1 ounce to each foot of a conditioned athlete increased his energy consumption by 14% during a 4-mile run. Thus, it is apparent that the saving of even a few ounces in overall skate weight represents a significant energy saving factor to a skater.
A further advantage of the present invention is that through the use of an extremely tough plastic, such as a polycarbonate, the blade-supporting body is not susceptible to denting, warping, chipping or rusting, all of which are common with a steel body.
The present invention relates to a new type of composite skate construction wherein the blade-supporting body or frame is made of a suitable thermoplastic material with a hardened steel blade uniquely fastened thereto and is a companion application to Ser. No. 608,499 filed Aug. 28, 1975. As indicated in U.S. Pat. No. 3,212,786 Florjancic et al., Canadian Pat. No. 585,780 Kirkpatrick et al. and Russian Pat. No. 123,068 Abelson, many efforts have been made to produce an ice skate employing a plastic blade-supporting body. Not withstanding the great potential advantages thereof, no one has heretofore successfully produced such a composite skate of commercial quality and particularly one that could withstand the extremely rigorous loads and abuse to which hockey skates are subjected.
Knowing of the superior performance qualities of a skate utilizing a plastic blade-supporting body, applicant sought a way to produce such a commercially feasible composite type skate. Applicant's original efforts resulted in a composite type skate having greatly improved performance characteristics. More specifically, the skates were lighter and far more responsive to the skater's demands. However, as with skates made according to prior art teachings, a serious problem developed with respect to fracturing or cracking of the plastic body. Such cracking either began immediately after manufacture or developed within a reasonably short time of use. After considerable experimentation, applicant discovered that while commercially available thermoplastic materials, such as those of the polycarbonate group, had more than enough inherent structural strength, the manner in which the hardened steel blade was joined to the plastic body was critically important. Applicant found in his earlier designs, like those of the prior patented art, that when the plastic body is initially molded and mechanically interlocked with the skate blade, severe localized stresses are set up in the plastic. It was further found that from these highly stressed areas cracks emanated which eventually caused the body to fail or sufficiently disrupted its appearance as to cause the user to lose confidence in its safety.
Thus, the present invention is directed to a composite skate design utilizing a thermoplastic blade-supporting body joined to the skate blade in such a way as to eliminate such critical stress areas within the plastic body thereby preventing cracking or fracturing of the body.
Hockey players who have tested skates made in accordance with the subject invention under playing conditions claim they sense more "life" or responsiveness in the blades. It is assumed that this reaction may be attributable to the greater flexibility of the plastic body/steel blade assembly combined with its lighter weight as compared to its all-steel counterpart.